Runner wheel for turbines, etc.



Oct. 21 1924.

V. KAPLAN RUNNER WHEEL FOR TURBINES ETC Filed Sept. 1 1921 FIG.

INUENTDRI WITNESSESI Patented Oct. 21, 1924.

UNITED sTATEs PATENT OFFICE.

vmron KAPLAN, or BRUNN, CZEGHbSLOVAKIA.

RUNNER FOR TURBINES, ETC.

Application-filed September 1, 1921. Serial No. 497,747.

T 0 all whom it may concern:

Be it known that I, VIK'roR KAPLAN, a

subject to the State of Czechoslovakia, residcentrifugal pumps, etc., and has for its more particular object improvements in the shape and relative position of the runner-blades,

whereby an increase in the number of revolu tions and in efiiciency is obtained. To this end, the blades are made so that the mean area of all the blades does not exceed onethird of the circular area determined by the diameter of the runner wheel. Moreover, the width of the blades measured in the direction of rotation decreases toward the free ends of the blades. I

In the accompanying drawing in which several runner-wheels, constructed according to the principle of my invention, are shown by way of example, Fig. 1 is the vertical projection of a runner-wheel equipped with four blades of equal shape and size and adapted for a general axial water-flow. Fig.- 2 is the horizontal projection of the wheel shown in Fig. 1. Fig. 3 shows a runnerwheel equipped with only two blades of equal shape and size, while Fig. 4 illustrates the horizontal projection of said runnerwheel.

In the modern construction of water turbines care must be taken to so regulate the turbine that a definite permissible moment of the force is not continually exceeded. In the case where an electric generator is driven by a turbine, it is well-known, that the generator is only designed for a certain highest speed, which must not be continually exceeded for the simple reason that the generator would be destroyed by the heat of the generator-windings. The usual regulating devices cannot overcome this drawback but, on the contrary, increase it, becausean increasing moment of resistance on the part of the generator causes a reduction of its number of revolutions, which can only be v compensated by a renewed increase of the moment of the force. The said drawback can however be avoided, if the capacity of overloading of the generator is made to harmonize with that of the turbine. Figs. 1 and 2 show a runner-Wheel of a water- 'turbine intended for. high specific speeds. The wheel, therefore, has onlyv four, either fixed or adjustable, blades, whose entire blade surface (F) does not exceed a third I of the circular area as determined by the diameter D of the runner wheel. In this case, the disturbance of the normal flow through the runner-wheel is very slight, and a continual and considerable increase of the turning-moment causes a disturbance of the normal flow, producing a reduction of the moment of the force, not an increase. By such an arrangement, the above mentioned danger of the enerator being destroyed is effectually avoi ed. The said proportion of blade-surface and circular-area must of course not be considered a fixed limit. On the contrary, there is a gradual variation, depending on the size of the runner-wheel, its roughness, and other in'the case of variable admission.

The shape 'of the blades one must determine according to three dimensions, height, depth and width, taking into consideration the water friction, if the theoretically calculated amount of water and number of revolutions are to be brought into agreement with the practical tests. For this reason, in the case of especially high specific speeds, a reduction in the width of the runnerblades toward the suction-tube or 'toward theirfree ends is necessary, in order to reduce the frictional resistance.

By the mean area F of the blades, the mean-value of the front and rear surface (f and f Figs. 1 to 4) of the blades is meant. In the case of Figs. 1 and 2, therefore,

Whereas in the case of Figs. 3 and 4 Of course, the mean areas of the various runner-blades need not be alike, as long as the mean area of all the blades does not exceed one-third of the circular area referred to. This circular area determined by the diameter D is fixed by the area of the circle which lies in a plane perpendicular to the turbine shaft, which circle is described by the blade-ends most distant from the runner shaft (Figs. 1 and 4). The manner and direction of the Water-flow through the runnerwheel may be varied, as long as the runnerwheel is combinedwith devices as are absolutely necessary to obtain a Well-controlled flow Without the least possible loss. If such a runner-Wheel is to be mounted in a turbine, a properly shaped guiding-device must be Provided. to rovide for a wel -remilated water-supply. A suction-tube must also be provided for the discharge of the Water, which must permit of a corresponding re"- covery of power through the suction-tube.

I claim as my invention:

1. Runner Wheel for turbines and the like comprising blades the mean area of all of which is not greater than one-third of the circular area determined by the diameter of the runner Wheel.

2. A runner wheel for turbines and the like as set forth in claim 1 comprising only two blades.

v 3. A runner Wheel for turbines and the like as set forth in claim 1, in Which'the Width of the blades measured in the direction of rotation decreases toward the free end of the blades.

In testimony whereof I aflix my signature in presence of two witnesses.

VIKTOR KAPLAN. Witnesses:

MARIXUM KNY,

D. HU'ITERLY. 

